Hey Veahlove32,
Lets solve your problem step by step.
[tex](-21)+(-9)[/tex]
To solve the problem we have to follow the PEMDAS order of operations.
Key note to remember: Negative plus negative is always negative.
[tex]\mathrm{Apply\:rule\:}+\left(-a\right)\:=\:-a[/tex]
Therefore, [tex]\left(-21\right)-9=-30[/tex]
[tex]=-30[/tex]
Hope this helps,
AnthrαX
